scons: add code to generate the various GL API files
This fixes recent build breakage when we began building the generated
API files from xml as part of the normal build process.
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=50475
diff --git a/src/SConscript b/src/SConscript
index 3d00878..75c4446 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -16,6 +16,7 @@
# used. libgl-xlib and libgl-gdi adapt themselves to use the targets defined
# in mapi/glapi-shared/SConscript. mesa/SConscript also adapts itself to
# enable OpenGL ES support.
+SConscript('mapi/glapi/gen/SConscript')
SConscript('mapi/glapi/SConscript')
SConscript('mesa/SConscript')